AU2018101785A4 - Multi Active Liquid Carbon Dioxide Aerosol - Google Patents

Abstract

Multi Active Liquid Carbon Dioxide Aerosol Abstract There is an industry need to improve the efficacy and cost effectiveness of existing automatic space spray products currently used in food storage and warehouses Improved efficacy and cost effectiveness can be achieved by using this innovation This innovation allows new products to be formulated in the future

Description

EDITORIAL NOTE

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Multi Active Liquid Carbon Dioxide Aerosol

2018101785 19 Nov 2018

This innovation enables the formulation of new pesticide in liquid carbon dioxide (LCO₂) aerosols products to treat food storage and warehouses. The use of appropriate co-solvents overcomes miscibility, stability, and solubility issues of both liquid and solid pesticides (e.g. Deltamethrin).

While the preferred co-solvents are both volatile and flammable the formulated mixture maintains the non-flammable benefit of the LCO₂ solvent-propellant. Volatile solvents avoid any issue of oily deposits build-up on surfaces. Cooling of the liquid aerosol droplet at the nozzle by evaporation of LCO₂on exposure to atmospheric pressure ensures a stable aerosol droplet. The LCO₂ is maintained as the dominant component to ensure non-flammability.

The pesticide active is initially dissolved in the co-solvent, which needs to be compatible with the LCO₂ solvent-propellant system. On dispensing via a metering orifice nozzle the LCO₂ evaporates forming liquid aerosol particles containing the dissolved solid insecticide ingredient. The surface area of the two micron (2μ) droplet is large compared to its volumes so the potential for high vaporisation of the solvent exposing solid active ingredient snowflakes is an issue. However the LCO₂ evaporation chilling temperature (minus -78°C) ensures cooling of the liquid droplets to retard evaporation of the co-solvent from the liquid/solid aerosol particle. The innovative selection of solvent and solid active ingredient concentration in the LCO₂ system mitigates against these issues ensuring uniform distribution of an effective dosage. The LCO₂ ensures the elimination of flammability issues even when a very flammable co-solvent is used in the formulation. There are no issues with pressure ratings because of the use of high pressure industrial gas cylinders and pressure rated pipework for the automated dispensing of the LCO₂ insecticide mixture. Industrial gas cylinders are rated for much higher pressure than the medium pressure of LCO₂ (150 bar V's 50 bar). The final mixture delivers a self-powered space spray with superior aerosol particle sizes suspended for up to two hours with no flammability, odour, staining, toxicological and pollution concerns.

In aerosol products, the propellant is the driving force and liquefied gases are preferred. The choice of aerosol propellant include hydrocarbons (LPG), dimethyl ether (DME), Chlorofluorocarbons (CFCs), Hydrofluorocarbons (HFCs), Hydrofluorolefins (HFO) and Liquid Carbon Dioxide (LCO₂). Consideration of the large spaces to be treated, component flammability and cost issues resulted in selecting the inert, non-flammable, low cost LCO₂ (high pressure containers and dispensing equipment are offset by a more suitable-for-purpose product).

The challenge was to formulate a new insecticide active ingredient into an effective aerosol formulation. The need was satisfied by developing a suitable, stable and effective LCO₂ formulation of a both liquid and solid active insecticide constituents into an agricultural aerosol space spray. The issues of powder insecticide formulation with potential equipment blockages and use of complex mixtures of solvents, surfactants and adjuvants was avoided. The selection of the non-polar LCO₂ solvent-propellant allowed selection of the most effective co-solvent without any flammability concerns in the innovative minimalist formulation. The successful homogeneous single LCO₂ phase resulted in mutual solubility and stability of the multicomponent liquid-solid system over a wide ambient temperature range. The solid aerosol formulation adapted a co-solvent to ensure a homogeneous liquid phase, which achieves uniform dispensing of a consistent and predictable dose. Example: LCO₂ aerosol containing pyrethroid Deltamethrin/LCO₂ which flushes and kill insects through direct contact is dispensed using manual spray gun or automatic system using fixed pipeline and dispensing nozzle system. The dispensed aerosol forms small spherical liquid particle to achieve efficacy and uniform targeted distribution. The product could also be mixed on-site using LCO₂ and co-solvent/solid solution in high pressure venturi device.

2018101785 19 Nov 2018

EDITORIAL NOTE

There is one page in the claims only .

2018101785 19 Nov 2018

Multi Active Liquid Carbon Dioxide Aerosol

Claims (1)

1. Claims • Formulate insecticide active ingredients into an effective liquid carbon dioxide aerosol • Solid insecticide active ingredient dissolved in a co-solvent / liquid carbon dioxide formulation • Liquid carbon dioxide as the dominant component insures non-flammability • Use of co-solvent to achieve miscibility, stability and solubility in liquid carbon dioxide • Solid insecticide active ingredient formulations avoid equipment and nozzle blockages • Volatile flammable co-solvents minimizes oily deposits • Stable aerosol droplets achieved by cooling at the dispensing nozzle • Operator exposure eliminated using automatic controlled spraying • Option to use a pre-mix cylinder or on-site mixing • Can be adapted to existing space spray dispensing systems • Accurate dose metering by orifice and or dose cylinder